Portable dynamometer anchoring station for measuring strength of the hip extensors and abductors

Objective: To assess the reliability of a specially designed dynamometer an choring station in the measurement of hip muscle strength. Design: Prospective study using test-retest design, Setting: Outpatient clinic setting. Participants: Ten subjects, ages 25 to 35yrs. Main Outcome Measures: Using the apparatus, three consecutive measures were recorded for hip abduction and extension by an inexperienced examiner. Two weeks later, the same subjects were retested, with the evaluator blinded t o the initial results. In both the test and retest, average and maximal val ues of strength were calculated for each muscle, Reliability of the device was assessed by computing the intraclass correlation coefficients and coeff icients of variation (CVs). Results: Intraclass correlation coefficients ranged from .94 to .98. The av erage CV for the maximal and average abduction strength had values of 4.77% and 4%, respectively. The maximal and average extension strength had avera ge CV values of 8.06% and 7.83%, respectively. Conclusion: This specially designed dynamometer anchoring station has been found to be highly reliable in the measurement of hip girdle strength and h as the advantage of easy adjustability and portability for large-scale scre enings. This device enhances the reliability of the dynamometer, which may be subject to considerable variability when applied by hand to the powerful hip girdle musculature.